Trenz Electronic GmbH Support Forum

Trenz Electronic Products => Trenz Electronic FPGA Modules => Topic started by: ktonchev on May 09, 2019, 04:36:50 PM

Title: TE0720 secure reboot from linux
Post by: ktonchev on May 09, 2019, 04:36:50 PM
Hello,

we are using TE0720 for our application running custom linux built using Yocto. The FSBL and bitstreams are encrypted (the key is in eFUSE) and we we've found out that in this situation, when one performs reboot from linux the device enters secure lockdown (which is the expected behaviour). The proper way according Xilinx is to execute POR_B reset instead of PS reset only, this however requires additional hardware.We've found out a topic in Xilinx where is mentioned that the CPLD on TE0720 can perform POR_B reset from software:

https://forums.xilinx.com/t5/Embedded-Processor-System-Design/System-reset-in-secure-boot/td-p/672511

However, in the documentation of the CPLD is not mentioned how to execute POR_B reset from software or use any other watchdog functionality mentioned. We will appreciate if you can tell us how to use such CPLD functionalities.

Thanks,
Krasimir




Title: Re: TE0720 secure reboot from linux
Post by: JH on May 10, 2019, 11:42:57 AM
Hi,
POR_B i set low with EN1 (B2B EN1 Pin - JM1-28), RESIN (B2B RESIN Pin LM2-18) or if some power failed.

br
John